Radio frequency (RF) signals are commonly switched between source and destination devices using an RF router (or RF routing switcher). The purpose of an m×n RF router is to allow the user to connect RF signals from up to “m” source devices to as many as “n” destination devices. Some devices may be both source and destination devices and may be coupled to both one or more inputs of a RF router and to one or more outputs of the RF router. The variable “m” refers to the number of RF input signals the router can accommodate; “n” refers to the number of outputs the router supports. The number of inputs and outputs that a RF router can handle is often referred to as the size, format or dimension of a router. For example, a router capable of routing 64 inputs to 32 outputs has a size or format of 64×32.
Through a controller (which may be integrated with the router or may be externally coupled to the router), an m×n RF router can be configured to direct any of its m inputs to be routed to any combination of its n outputs. This enables the user to connect RF source devices to the router's inputs, and RF destination devices to the router's outputs, and make and break connections without having to rewire the circuit every time that a new configuration is desired.
RF signals are used to transmit increasingly complex data signals. For example, digital audio/video signals for high definition television contain significantly more information than older forms of RF signals such as AM radio. In addition, many more signals must be processed in modern signal processing systems. In some regions, hundreds of signals are available for viewing or listening. Due to the prevalence of the use of RF signals to transmit data, and the corresponding increase in complexity in RF signal networks, there is a need for m×n RF routers where m and n are equal to greater than 32.
While RF routers with 32 inputs and 32 outputs are known in the art, there are several undesirable features of previous designs. RF routers with high numbers of inputs and outputs typically are physically very large, due to the common practice of using active components to divide incoming signals. The use of a large number of active components increases the amount of energy consumed by a typical router, and simultaneously increases the likelihood of malfunction. Other devices use Wilkinson splitters to divide incoming signals. Wilkinson splitters are also physically large devices and occupy substantial space on a circuit board. As a result, RF routers that utilize Wilkinson splitter are also physically large and have other disadvantages.
RF routers are often designed to fit into a 19 inch wide rack. Such device may have various heights, generally in multiples of rack units (which are 1.75 inches high). The large physical size of the signal splitting devices limits the number of inputs and outputs that can be provided in a standard or practically sized unit. To assemble routers with a larger number of inputs or outputs (or both) than a particular design can provide in a practical size, multiple individual routers are often coupled together, with the result that substantial space is required to provide such routers. Such modular routers require an external active switching component, which requires external control with a correspondingly higher cost and a higher likelihood of malfunction.
Accordingly, there is a need for a large format RF router that is compact, energy-efficient, low-cost and that has a low likelihood of malfunction.